Guitar vibrato device



Jan. 21, 1969 5, PORTER 3,422,509

GUITAR VIBRATO DEVICE Filed Oct. 22, 1965 I9 I I3 ,DQNALD 5,2 0 El? 6y L j ll IQTTOQNEY United States Patent 13 Claims ABSTRACT OF THE DISCLOSURE A vibrato device for a guitar or other stringed instrument, including a string anchoring unit to be connected to the strings, and mounted for resilient pivotal movement to vary the tension on the strings and thereby change their pitch slightly to give a vibrato effect, a handle for actuating the anchoring unit pivotally about its axis, and a friction connection between the handle and the anchoring unit for transmitting pivotal motion from the handle to the anchoring unit to vary the pitch, but with the friction connection being of limited torque transmitting capacity adapted to be overcome by the handle to swing the handle to different settings relative to the anchoring unit, so that the device can produce a vibrato effect in any of various different positions of the handle.

This invention relates to an improved vibrato device for use with a guitar, for the purpose of controllably varying to a slight degree the pitch of the strings as the instrument is being played.

There have in the past been devised various different types of vibrato devices for guitars, usually actuated by a handle which is received adjacent the strings of the instrument, so that a person playing the instrument may move the handle when desired in order to alternately decrease and increase the tension of the strings, and thereby produce a vibrato effect. One problem encountered in the use of such prior devices has resided in the difficulty encountered in adjusting the handles of these devices to different angularities with respect to the surface of the guitar and its strings, for the purpose of facilitating use by different persons having different sized hands and different playing techniques, or to enable use in different ways by the same person. Additionally, when storing the instrument within a guitar case, it is often very difficult if not impossible to properly close the case while the handle of the vibrato device is in its playing position, and consequently problems have been encountered in providing for retraction of the handle during storage into sufficiently close proximity to the outer face of the guitar to enable closure of the guitar case.

The various prior vibrato devices with which I am familiar have either provided no means whatever for adjusting the position of the handle relative to the guitar, or have permitted adjustment of the handle only by releasing a set screW or other holding mechanism, and then retightening that mechanism in a newly adjusted setting. This tightening of the set screw or other locking element has usually required a tool, and has therefore been very inconvenient for the person playing the instrument, particularly when it has become necessary to reset the handle while playing.

A major object of the present invention is to provide an improved vibrato arrangement in which the actuating handle may be very easily adjusted to any of numerous different settings relative to the guitar and its strings, to accommodate different playing techniques, etc, and with this adjustment being made without the necessity for tools of any type. As will appear, the handle is adjusted with no change in any set screw or other holding element, and in an instantaneous manner, by merely swinging ice the handle with slightly more force than that utilized during playing, and from one position to another.

This resetting of the handle maybe made repeatedly and as frequently as it becomes desirable, and is so quickly made as to allow shifting of the handle even while the instrument is being played, as for instance for the purpose of swinging the handle to an inactive setting when the music being played does not require the vibrato effect, and then suddenly swinging the handle into active position whenever vibrato is desired.

Structura lly this result is attained by providing a friction connection between the handle of the device and a resiliently deflecting string anchoring structure to which the ends of the guitar strings are connected. This anchoring structure may be spring urged to maintain the strings of the guitar under appropriate tension, and may be deflectible, desirably about an axis disposed transversely of the strings, to slightly vary the tension of the strings and produce the vibrato effect. The friction connection between the handle and the string anchoring unit affords sufficient friction between these parts to enable the handle to pivot the anchoring unit under normal playing conditions to introduce vibrato into the string pitch, and yet the friction between the parts is also sufficiently light to enable it to be overcome by the exertion of an increased force against the handle, so the handle may-be actuated when desired to a changed setting relative to the anchoring element. In that changed setting, the friction connection again will transmit vibrato tension varying forces from the handle to the anchoring unit and the strings, but may at any time be overcome to again reset the handle. A particular advantage of the arrangement resides in the fact that the adjustment of the handle to any changed setting does not alter the basic pitch of the strings.

The friction connection may consist of a shaft having a tubular structure disposed about the shaft and frictionally engaging it. This tubular structure may be tightened against the shaft by the force of the strings, in order to attain maximum simplicity and yet a reliable and predeterminable friction force. Preferably, the shaft is carried by the handle, and the tubular structure is carried by and for best results is integral with the anchoring unit, with the strings extending from anchoring apertures in the unit, and about the tubular structure to constrict it against the shaft.

In combination with this friction connection, there may be provided a second pivotal connection for mounting the handle to swing about a second axis, in order that it may move laterally relative to the strings, between a position adjacent or overlying the strings and a laterally retracted position.

The above and other features and objects of the invention will be better understood from the following detailed description of the typical embodiment illustrated in the accompanying drawing, in which:

FIG. 1 is a plan view of a guitar having a vibrato device constructed in accordance with the invention;

FIG. 2 is a fragmentary enlarged partially sectional view of the vibrato device;

FIG. 3 is a fragmentary side view taken on line 33 of FIG. 2;

FIG. 4 is a fragmentary transverse section taken on line 4-4 of FIG. 2;

FIG. 5 is a side view, partially in section, of the second pivotal joint, taken on line 5-5 of FIG. 2;

FIG. 5a is a view taken on line Sat-5a of FIG. 5;

FIG. 6 is a perspective representation of the mounting of the vibrato device; and

FIG. 7 is an enlarged side view taken on line 77 of FIG. 1.

Referring first to FIG. 1, I have shown at a conventional guitar, typically having a hollow type body 11 with the usual arm 12, and with the strings 13 connected at their outer ends to the tuning pins or knobs 14. The second ends of the strings are connected to a vibrato device 14 constructed in accordance with the invention, so that the strings are maintained under tension and produce notes of the desired pitches. Between their two ends, and near the vibrato device, the strings pass over a conventional bridge element 15 which projects outwardly from the main face or surface 16 of body 11.

The vibrato device includes a support structure 17 adapted to be mounted to the body 10 of the device in fixed position relative thereto. This support structure 17 may include a rigid planar metal plate element 18, overlying a portion of the surface 16 of guitar body 11, and carrying two upstanding spaced bearing blocks 19, which may be integral with plate 18 or rigidly brazed or otherwise secured to that plate. These bearing blocks 19 may contain two axially aligned typically identical bushings or bearings represented at 20, which may take the form of sleeves disposed about an axis 21 which extends essentially transversely of the longitudinal axes of strings 13.

Journalled within bearings 20', there is provided an elongated externally cylindrical shaft 22, of rigid and relatively strong material, such as an appropriate steel or other metal, so that shaft 22 is mounted to turn about axis 21. The shaft should be retained against axial movement relative to the bearings, as by provision of snap rings 23 within grooves in the shaft, at outer sides of the bearings, and with the bearings being appropriately retained against axial movement, as by forming the hearings to be press-fits within bearing blocks 19.

Shaft 22 is adapted to be turned pivotally about axis 21 by means of an elongated handle 24 which projects radially from and relative to axis 21 in the manner illustrated in the figures. To enable lateral shifting movement of the handle toward and away from the strings, the handle is pivotally connected to the shaft by a connection 25, to swing for example between the full line and broken line positions of FIG. 1, and beyond those positions in both directions, about an axis represented at 26 in FIG. 5. To form this connection, shaft 22 may be bent through 90 degrees at 27 (FIG. 2), to form a portion 28 projecting radially outwardly from axis 21, and having an externally cylindrical enlargement 29 pivotally connected to an enlarged fitting 30 carried at the inner end of handle 24. Fitting 30* may have a cylindrical recess 31 at its underside which rotatably receives and journals enlargement 29 of the shaft, and whose peripheral wall is interrupted across the rear side of the recess, with the shank 33 of a headed fastener 34 projecting downwardly through passages 35 and 36 in elements 30 and 29, to mount the handle for the desired pivotal motion about axis 26. A screw 37 may extend upwardly through portion 29 of the shaft, and be threadedly connected into shank 33, to retain the pivotally interconnected parts against relative separation. A friction ring or disk 38 may be interposed between the opposed planar surfaces of elements 29* and 30, and may be formed of nylon, polyethylene, or other suitable material having suflicient friction to hold the handle in any desired setting when screw 37 is appropriately tightened. At the underside of portion 29 of the shaft, there may be provided a typical sheet metal element 39', against which the head of screw 37 is engageable, and which has a tab 40 projecting into a recess 41 in fitting 30, to retain element 39 against rotation, so that the engagement of the head of screw 37 with element 39 will retain the screw in any desired setting, to thereby enable adjustment of the friction of the handle mounting connection, and assure retention of the adjusting screw 37 in a desired friction setting.

Handle 24 may be formed primarily of an elongated rod, having threads 7 0 at its end connected into a threaded passage 71 which is formed in fitting 30 and which extends through and perpendicular to axis 26 to the rear surface of fitting 30. A set screw 72 is threadedly connected into passage 71 and is tightenable against the end of handle 24 to engage it frictionally in a relation securing the handle rigidly to fitting 30'. This set screw is rendered accessible for installation and tightening through the rear end of passage 71 by removing fastener 34 from its position of blocking relation to passage 71, and separating fitting 30 from shaft 22, so that the passage is unobstructed to receive the set screw and an Allen wrench for turning the screw.

The ends of the strings which terminate at the location of vibrato device 14 have the usual enlargements 42, and are secured by these enlargements to a resiliently deflectible anchoring element 43 (FIG. 2). This anchoring element may be forced of essentially rigid sheet metal, such as an appropriate grade of steel, and may have the cross-section illustrated in FIG. 4. This cross-section may continue across the entire width of anchoring element 43, between its two opposite side edges 44 and 45, which edges are received closely adjacent the two bearing blocks 19. To define the cross-section of element 43 more specifically, and with reference to FIG. 4, it is noted that this element has a first essentially planar portion 46 disposed generally parallel to plate 18 of support structure 17, with portion 43 being yieldingly urged away from plate 18 by a series of coil springs 47, which are maintained under compression, and may be appropriately located by reception within shallow recesses 48 formed in the engaged parts. All of the springs 47 may be identical, and act to apply identical forces to element 43, sufiicient to maintain the proper tension on the strings 13. To the right of springs 47 in FIG. 4, element 43 may have a portion 49 which extends downwardly at an inclination, beyond which element 43 may extend generally parallel to plate 18 at 50, then upwardly at 51, and then essentially annularly about shaft 22 at 52. Internally, the tubular portion 52 of element 43 may have an inner cylindrical surface 53, of a diameter corresponding substantially to and frictionally engageable with the outer surface of shaft 22. The terminal edge 54 of tubular portion 52 of element 43 may terminate just short of the adjacent portion 51 of element 43, so that tubular portion 52 may be constricted radially inwardly against the shaft. Also, this radially inward construction may be facilitated by provision of a groove 55 extending parallel to axis 21, and forming a reduced thickness portion of the tubular structure 52. Near the lower extremity of portion 51 of element 43 (FIG. 4), there are provided within element 43 a series of apertures 56, spaced in correspondence with the spacing of the strings 13, and through which the strings extend rightwardly from their enlargements 42. After passing through apertures 56, the strings extend about tubular portion 52 of element 43, through approximately degrees or more, before extending rearwardly toward bridge 15. The material and thickness of portion 50 of element 43 is such as to give this portion a suflicient capacity for inward constrictability to enable the forces exerted by tensioned strings 13 to tighten portion 52 radially inwardly against shaft 22, to thus form a frictional connection between shaft 22 and tubular portion 52. Also, the leftward pull exerted by the strings on tubular portion 52 causes this tubular portion to exert a leftward force against the shaft, to in this way further increase the friction between the parts. It is contemplated that both of these frictional effects may be utilized, or in some instances only perhaps the latter effect may be employed, if the wall of tubular portion 52 is made sufficiently rigid to resist constriction. In any event, the arrangement allows predetermination of a reliably maintained frictional force between element 43 and shaft 22.

The support structure 17 may be secured to the body 11 of guitar 10 by an essentially U-shaped strap represented at 57 in FIG. 6, which may take the form of an elongated wire having two ends extending through passages 58 (FIG. 3) in the two bearing blocks 19 respectively, and having tightening nuts 59 threadedly connected to the ends of the wire beyond the bearing blocks and applying rightward forces to the bearing blocks. The two arms of strap 57 are designated 60 in FIG. 6, and may have an integral cross piece received within and extending transversely through a tubular portion 61 of a mounting bracket 62 which is secured by screws or other fasteners 63 to the end wall 64 of the guitar body. The support structure may also be secured to the guitar by screws 65 extending through appropriate apertures in plate 18 and extending into the body of the guitar, with this latter method of attachment being particularly desirable in the case of solid body guitars. When screws 65 are employed, strap 57 may be utilized in conjunction with these screws, or if desired the strap may be removed from the 'device by unscrewing nuts 59 from its opposite ends.

To now describe the manner of use of the device, assume that the vibrato attachment has been mounted to the guitar in the illustrated manner, and that the strings have been tuned properly. In playing the instrument with the vibrato, a user will normally position handle 24 in the setting illustrated in full lines in FIGS. 1 and 7, at an angle to the surfaces 16 of the guitar body, so that he may play the strings easily and yet have ready access to handle 24 when desired. Whenever he wants to introduce the vibrato eifect into a particular note, he merely grasps handle 24 and lightly presses it inwardly toward surface 16 of the guitar (downwardly in FIG. 7), or pulls it outwardly, sufficiently to lower or raise the pitch of the various strings 13 slightly, say for example through onehalf of a tone, By depressing or raising the handle 24 several times in this manner, the desired vibrato effect is attained. During this motion of handle 24, the friction between shaft 22 and tubular portion 52 of element 43 is sufi'icient to cause element 43 to move through exactly the same angle as does handle 24 and the connected shaft 22. That is, there is no slippage between the parts at the location of the friction connection during such vibrato operation. However, if it becomes desirable to swing handle 24 to a changed setting, as for instance to the broken line position of FIG. 7 when the guitar is to be placed in a case for storage, or to any other position of changed angularity with respect to the body of the guitar and the strings to facilitate manipulation by a different person or in a different manner, this result may be attained by merely forcing handle 24 with slightly increased force either upwardly away from the guitar body or doWnwardly toward the guitar body, and with sufficient strength to overcome the friction between shaft 22 and tubular portion 52 of element 43, so that the shaft may be moved to a new setting relative to element 43. In that new setting, the frictional connection between shaft 22 and portion 52 of element 43 again becomes effective to transmit torque from the shaft and its handle 24 to string anchoring element 43, without slippage, to a sufficient extent to enable the previously discussed vibrato action in the new setting of the handle, and without any change in the pitch of the strings resulting from the adjustment of the handle.

When the user desires to play the instrument without any contact at all with handle 24, he may swing the handle laterally to the broken line position of FIG. 1, or if he desires to play the instrument with handle 24 overlying the strings, he may swing the handle about axis 26 of FIG. to such a position of extension across the upper sides of the strings.

While the invention has been described solely as applied to guitars, it will be obvious that vibrato devices embodying the invention may also be used on any other similar stringed instrument. The term guitar in the specification and claims is therefore to be considered broadly as including any stringed instrument on which a vibrato eflect may be desired.

I claim:

1. A vibrato device for a guitar having strings, comprising a support structure to be mounted to the guitar, a string anchoring unit adapted to be connected to said strings at ends thereof and to hold them in tension and mounted for resilient essentially pivotal movement relative to the support structure about essentially a predetermined axis in a relation to vary the tension on the strings and thereby change their pitch slightly, a handle for actuating said anchoring unit about said axis, and a friction connection between said handle and said anchoring unit for transmitting pivotal motion from the handle to the anchoring unit about said axis but of limited torque transmitting capacity adapted to be overcome by the handle to swing the handle to different settings relative to the anchoring unit.

2. A vibrato device as recited in claim 1, in which said friction connection includes a shaft connected to and actuable by said handle, and a generally tubular structure connected to said string anchoring unit and disposed about and frictionally engaged by said shaft in a relation transmitting said pivotal motion from the handle to the anchoring unit through said shaft and said generally tubular structure.

3. A vibrato device as recited in claim 1, including spring means yieldingly resisting said pivotal movement of the string anchoring unit about said axis.

4. A vibrato device as recited in claim 1, in which said friction connection includes two frictionally engaging elements positioned to be urged together by the tension of said strings so that the strings increase the friction between said elements.

5. A vibrato device as recited in claim 1, in which said friction connection includes a shaft and a structure disposed about and frictionally engaged by the shaft and positioned and constructed to be at least partially encircled by the strings in a relation to be tightened against the shaft by the strings to increase the friction therewith.

6. A vibrato device as recited in claim 1, in which said friction connection includes a shaft extending essentially along said axis and essentially transversely of said strings, and connected to said handle for pivotal movement about said axis by the handle, and a structure carried by said string anchoring unit and forming essentially a constrictable tube disposed about said shaft in frictional engagement therewith.

7. A vibrato device as recited in claim .1, in which said friction connection includes a shaft extending essentially along said axis and essentially transversely of said strings, and connected to said handle for pivotal movement about said axis by the handle, and a structure carried by said string anchoring unit and forming essentially a constrictable tube disposed about said shaft in frictional engagement therewith, said string anchoring unit having apertures adjacent said tubular structure for receiving and anchoring said ends of the strings and from which the strings extend about said tubular structure so that the tension of the strings tends to constrict the tubular structure against the shaft, and pull it transversely of said axis, and thereby increase the friction between the shaft and the surrounding tubular structure.

8. A vibrato device as recited in claim 1, in which said support structure has a base plate, said anchoring unit being formed of sheet metal and having a plate portion disposed generally parallel to and spaced from said base plate of the support structure, there being spring means interposed between said base plate and said plate portion of the anchoring unit and yieldingly urging said anchoring unit about said axis in a direction to tighten the strings, said support structure having spaced bearings, said friction connection including a shaft actuable by the handle and extending along said axis and journalled by said bearings for turning movement about the axis, and an extension formed integrally with the sheet material of said anchor unit and projecting therefrom and forming essentially a tube disposed about said shaft and free for construction radially inwardly thereagainst to 'be frictionally turned by the shaft about said axis, said sheet maerial of the string anchoring unit having apertures through which said strings extend in anchored relation and from which the strings extend about said tubular structure in a relation constricting the tubular structure radially inwardly against the shaft under the influence of the string tension, said sheet material of the string anchoring unit having a weakened area extending along one side of said tubular structure to facilitate constriction of the tubular structure.

9. An instrument having strings, and a vibrato unit for controllably varying the tension of said strings, said vihrato unit including a first element mounted for predetermined movement and operable by such movement to vary the string tension, a handle element for actuating said first element, and a pivotal connection between said elements, said connection including a connector part containing a threaded bore, said handle having a threaded portion connected into said bore, a set screw in said bore tightenable toward said handle to lock the handle to said connector part, and means pivotally securing said first element to said connector part at a location blocking access to said bore and said set screw therein.

10. An instrument as recited in claim 9, in which said connector part contains an essentially circular recess opposite said bore and set screw, said last mentioned means of claim 9 including a connector lug formed on said first element and pivotally received in said essentially circular recess at a location blocking access to said bore, and fastener means extending axially through and interconnecting said connector part and said connector lug.

11. An instrument as recited in claim 10, in which said connection includes a disc received and clamped axially between said connector part and said lug to introduce a variable friction therebetween, said fastener means including a screw adapted by tightening to vary the force exerted on said disc and having a head near said lug, and said connection including a thin part received and confined axially between said lug and said head and interfitting with said connector part in a relation preventing relative rotary movement between the thin part and connector part.

12. An instrument having strings, and a vibrato unit for controllably varying the tension of said strings, said vibrato unit including a first element mounted for predetermined movement and operable by such movement to vary the string tension, a handle element for actuating said first element, and a pivotal connection between said elements, said connection including a connector lug carried by one of said elements, a relatively pivotal structure carried by the other element, a disc interposed between said lug and said structure for introducing a variable friction therebetween, a screw extending through said lug and disc and tightenable to adjustably secure said lug to said structure, said screw having a head received near said lug, and a sheet form part interposed between said head and said lug and having a tab received in a recess in said structure in a relation locking said sheet form part and said structure against relative rotary motion.

13. A vibrato device for a guitar having strings, comprising a support structure to be mounted to the guitar, a string anchoring unit adapted to be connected to said strings at ends thereof and to hold them in tension and mounted for resilient movement relative to the support structure in a relation to vary the tension on the strings and thereby change their pitch slightly, a handle for actuating said anchoring unit to vary said tension, and a friction connection between said handle and said anchoring unit for transmitting string tension varying motion from the handle to the anchoring unit, but of limited force transmitting capacity adapted to be overcome by the handle to move the handle to different settings relative to the anchoring unit.

References Cited UNITED STATES PATENTS 3/1964 Costen STEPHEN J. TOMSKY, Primary Examiner.

G. M. POLUMBUS, Assistant Examiner. 

